I have no Betta experience and 2 days ago I got my first. She is plump where the internal organs are but is skinny behind that. Is that normal or is she under weight? She is very active and has a healthy appetite. Do they need to be fed more than once a day? Sorry I can't post a pic.

Also, since you said you're really new, I think it would be beneficial to make sure everything else is in check. When it asks about water changes, just put what you plan on doing.

Housing
What size is your tank?
What temperature is your tank?
Does your tank have a filter?
Does your tank have an air stone or other type of aeration?
Is your tank heated?
What tank mates does your betta fish live with?

Food
What type of food do you feed your betta fish?
How often do you feed your betta fish?

Maintenance
How often do you perform a water change?
What percentage of the water do you change when you perform a water change?
What type of additives do you add to the water when you perform a water change?

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed?
How has your betta fish's behavior changed?
When did you start noticing the symptoms?
Have you started treating your fish? If so, how?
Does your fish have any history of being ill?
How old is your fish (approximately)?

Also, since you said you're really new, I think it would be beneficial to make sure everything else is in check. When it asks about water changes, just put what you plan on doing.

Housing
What size is your tank? 20g ,running 1 year, heavily planted
What temperature is your tank?78f
Does your tank have a filter?HOB
Does your tank have an air stone or other type of aeration?No
Is your tank heated? Yes
What tank mates does your betta fish live with? Snail population only

Food
What type of food do you feed your betta fish? Omega Betta Buffet
How often do you feed your betta fish? 2x daily

Maintenance
How often do you perform a water change? Weekly
What percentage of the water do you change when you perform a water change? 25%
What type of additives do you add to the water when you perform a water change? Prime

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Symptoms and Treatment
How has your betta fish's appearance changed? It hasn't, I bought her 2 days ago.
How has your betta fish's behavior changed?
When did you start noticing the symptoms?
Have you started treating your fish? If so, how?
Does your fish have any history of being ill?
How old is your fish (approximately)?

New to me , she's about 1 1/2''. She looks skinny but is very active and has a good appetite. When viewed from above she is visibly thin and her head is 2x wider than the body. Is this normal for Betta? If not should I feed her more? Does a Betta need as much food as a comparable sized fish? Sorry I can't post pics.

It's hard to tell without a pic, but I'll imagine. Male and female betta bodies are really different. Males are typically thinner than females. How many pellets do you feed her when you do?

As you can see, body size is different on any female betta (included pic - my girls are in a sorority, so some eat more than others. Just depends on who gets to the pellet first). My males get specific amounts, though, since they're in their own tanks (which is what I would suggest for your girl). If she isn't very old, she will have a smaller body. She should thicken out as she gets older. Smaller fish usually get two pellets at feeding time, and larger fish get four. Larger fish are really big, so they naturally need more food. Bettas don't really eat a lot since they can get constipated so easily. Due to this reason, most owners will suggest fasting for a day.

Thank you for the pics. Mine looks a lot like your white and purple,and white and red Betta. Maybe she's not as skinny as I thought. I fed her about 5 pellets per day. When you say pellets do you mean the Omega Buffet pellets I have? Can she eat Tetra sun dried baby Gammarus shrimp?

I used to have those shrimp - my bettas have always treated them with extreme disdain, and I was warned off them for some reason - from memory I think they were likely to cause bloating(?).

Females do tend to be a little round at the front and slimmer at the back, but a picture of your girl would really help us confirm that nothing is wrong. :) Lucky fish, having a 20 gallon all to herself!

My female VT started out small and skinny, kind of like Hadoken Kitty's white with purple girl. I've had her for about 7 months now, and she's grown larger and filled out, as well. Now she looks more like Hadoken Kitty's white with turquoise girl (the first just above the white with red girl). So it could also be that your girl is young still, and has more growing to do.

I feed my bettas Omega One Betta Buffet pellets, also. My female gets 5-6 per day, split into two separate meals. Some people fast one day per week. I don't do this, but I also don't give her other treats. (Although, once the weather gets warmer again, I'll hunt up some mosquito larvae for my guys.)

I used to have those shrimp - my bettas have always treated them with extreme disdain, and I was warned off them for some reason - from memory I think they were likely to cause bloating(?).

Females do tend to be a little round at the front and slimmer at the back, but a picture of your girl would really help us confirm that nothing is wrong. :) Lucky fish, having a 20 gallon all to herself!

Thank you, I won't feed those shrimp. She seems to like having the tank to herself. We were amazed that she didn't need time to get used to the tank . Within 15 minutes she was knocking pond snails off of the glass and physically trying to pick fights with the larger ramshorns. Now I see why everyone loves Bettas, we should have gotten one a long time ago.

My female VT started out small and skinny, kind of like Hadoken Kitty's white with purple girl. I've had her for about 7 months now, and she's grown larger and filled out, as well. Now she looks more like Hadoken Kitty's white with turquoise girl (the first just above the white with red girl). So it could also be that your girl is young still, and has more growing to do.

I feed my bettas Omega One Betta Buffet pellets, also. My female gets 5-6 per day, split into two separate meals. Some people fast one day per week. I don't do this, but I also don't give her other treats. (Although, once the weather gets warmer again, I'll hunt up some mosquito larvae for my guys.)

Mosquito larvea sounds like a good idea. There's millions of them in north Texas.Thanks.